POS0605 IN PATIENTS WITH RHEUMATOID ARTHRITIS, CLINICAL EXAMINATION OF THE FEET IS IMPORTANT FOR UNDERSTANDING INDIVIDUAL DISEASE BURDEN, BUT DOES NOT PROVOKE A CHANGE IN THERAPY IN MOST CASES
Authors: N. Leuchten, C. Weinert, M. Aringer
Journal: Annals of the Rheumatic Diseases (2022)

Background Disease activity scores like CDAI, SDAI or DAS28, are essential for measuring rheumatoid arthritis (RA) disease activity. These do not contain foot joints. However, foot pain is an important aspect of morbidity for RA patients, which leads to reduced mobility and quality of life. Objectives To analyse the impact of synovitis in ankle and metatarsophalangeal joints on RA scores and RA disease activity states. Methods Joint scores of 545 RA outpatients were followed from August 2004 through December 2020. Informed consent for the analysis of their routine data was obtained for every patient. The standard CDAI cut-offs used were CDAI ≤ 2.8 for remission (REM), CDAI &gt; 2.8 - 10.0 for low disease activity (LDA), CDAI &gt; 10.0 - 22.0 for moderate disease activity (MDA) and CDAI &gt; 22.0 for high disease activity (HDA). Foot involvement (FI) was defined as having at least one swollen (SJ) or tender (TJ) foot joint in patients who ever had palpable synovitis in any of these joints. The visits were grouped according to the number of swollen joints (SJ 0-28). The mean Physician Global Assessment of disease activity (PhGA) was calculated for each SJ group and the difference between the mean PhGA in patients with and without FI (as defined above) was calculated for each SJ group (ΔPhGA). Statistical analysis was performed in IBM SPSS Statistics Version 28.0.1.0. Results A total of 7,577 visits of 545 patients were included, for a mean of 14 visits per patient. 413 (75.8%) of the patients were female, the mean age at visit was 59 years, mean disease duration was 13 years, 284 (52.1%) were ACPA positive. 247 (45.3%) were on glucocorticoid therapy, 50 (9.2%) were on biological DMARDs. The median CDAI at visit was 4.3 (interquartile range IQR 1.6 - 9.0), the median DAS28 was 2.56 (IQR 1.89 - 3.37), the median CRP was 2.5 (IQR 1.0 - 6.2) mg/L. At 2,853 (37.7%) visits the patient was in REM, at 3,134 (41.4%) visits in LDA, at 1,265 (16.7%) visits in MDA and at 324 (4.3%) visits in HDA. Patients with FI were more active and scored higher on CDAI (9.1 vs. 3.4, p&lt;0.001) and DAS28 (3.19 vs. 2.45, p&lt;0.001), even though the indices do not include the foot joints. This was mainly due to higher patient global assessment of disease activity (3.1 vs. 2.0, p&lt;0.001). Involvement of the feet also led to a higher physician estimate of global disease activity. The mean difference of PhGA between patients with and without involvement of their feet (ΔPhGA) was meaningful for joint counts 0-10, with an unweighted mean ΔPhGA of 0.273. Of the 217 patients with FI, 3,776 visits were analyzed. For patients with FI, the potential change in disease activity was calculated by subtracting ΔPhGA from the CDAI at each visit. For 3,662 (97.0%) of the visits, this did not result in a change of disease activity state. For 90 (2.4%) visits, disease activity changed from LDA to REM, for 21 (0.6%) from MDA to LDA, and for only 3 (0.1%) visits from HDA to MDA. At 83 (1.1%) visits of a total of 59 (10.8%) patients, only swollen foot joints without tender foot joints were recorded. Conclusion Patients with foot involvement are more active and score disproportionally high on disease activity indices, even though these do not include foot joints. While patients suffer significantly from foot involvement, underestimating disease activity by not assessing the feet would have changed the disease activity state for 3.1% of the visits only. Palpable synovitis without tenderness, which would be missed by performing only a metatarsophalangeal squeeze test, was found at one in a hundred visits. References [1]Kapral et al. Remission by composite scores in rheumatoid arthritis: are ankles and feet important?. Arthritis Res Ther 9, R72 (2007). https://doi.org/10.1186/ar2270 Figure 1. Disclosure of Interests Nicolai Leuchten Speakers bureau: Abbvie, AstraZeneca, BMS, Boehringer Ingelheim, Chugai, GSK, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, UCB. Consultant of: Abbvie, AstraZeneca, BMS, Boehringer Ingelheim, Chugai, GSK, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, UCB., Christoph Weinert: None declared, Martin Aringer Speakers bureau: AbbVie, Astra Zeneca, BMS, Boehringer Ingelheim, Chugai, Galapagos, GSK, HEXAL, Lilly, MSD, Mylan, Novartis, Otsuka, Pfizer, Roche, Sanofi, UCB., Consultant of: AbbVie, Astra Zeneca, BMS, Boehringer Ingelheim, Galapagos, GSK, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, UCB.